Buggy code:
public class Shell { private static final String INPUT_LINE_INDICATOR = ">><seq2seq4repair_space>" ; private static final String SYSTEM_OFF_ALERT = "ChronoTimer<seq2seq4repair_space>system<seq2seq4repair_space>is<seq2seq4repair_space>OFF" ; private ChronoTimer chrono ; private List < Sensor > sensors ; private String [ ] args ; public Shell ( ) { } public void run ( ) { } private void execute ( String [ ] arg ) { switch ( arg [ 0 ] ) { case "RESET" : chrono = new ChronoTimer ( ) ; break ; case "TIME" : Time . setTime ( arg [ 1 ] ) ; break ; case "TOG" : if ( isNum ( arg [ 1 ] ) ) { try { chrono . toggle ( Integer . parseInt ( arg [ 1 ] ) ) ; } catch ( IndexOutOfBoundsException e ) { System . out . println ( e . getMessage ( ) ) ; } } else { System . out . println ( ( ( arg [ 1 ] ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>a<seq2seq4repair_space>valid<seq2seq4repair_space>channel" ) ) ; } break ; case "CONN" : if ( isNum ( arg [ 1 ] ) ) { try { int index = Integer . parseInt ( arg [ 1 ] ) ; Sensor sensor = new Sensor ( ) ; try { sensors . add ( ( index - 1 ) , sensor ) ; } catch ( Exception e ) { System . out . println ( "No<seq2seq4repair_space>such<seq2seq4repair_space>sensor" ) ; } chrono . connect ( index , sensor ) ; } catch ( NoSuchElementException e ) { System . out . println ( e . getMessage ( ) ) ; } } break ; case "DISC" : if ( isNum ( arg [ 1 ] ) ) { try { int index = Integer . parseInt ( arg [ 1 ] ) ; chrono . disconnect ( index ) ; } catch ( NoSuchElementException e ) { System . out . println ( e . getMessage ( ) ) ; } } break ; case "EVENT" : break ; case "NEWRUN" : try { chrono . newRun ( ) ; } catch ( Exception e ) { System . out . println ( e . getMessage ( ) ) ; } break ; case "ENDRUN" : try { chrono . endRun ( ) ; } catch ( Exception e ) { System . out . println ( e . getMessage ( ) ) ; } break ; case "PRINT" : if ( ( arg . length ) >= 2 ) { if ( isNum ( arg [ 1 ] ) ) { try { chrono . print ( Integer . parseInt ( arg [ 1 ] ) ) ; } catch ( NoSuchElementException e ) { System . out . println ( e . getMessage ( ) ) ; } } else { System . out . println ( ( ( arg [ 1 ] ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>a<seq2seq4repair_space>recognized<seq2seq4repair_space>run<seq2seq4repair_space>number" ) ) ; } } else { <START_BUG> System . out . println ( "No<seq2seq4repair_space>run<seq2seq4repair_space>specified" ) ; <END_BUG> } break ; case "EXPORT" : break ; case "NUM" : if ( ( ( args . length ) > 1 ) && ( isNum ( args [ 1 ] ) ) ) { try { chrono . num ( Integer . parseInt ( args [ 1 ] ) ) ; } catch ( IllegalArgumentException e ) { System . out . println ( e . getMessage ( ) ) ; } } else { System . out . println ( "Enter<seq2seq4repair_space>a<seq2seq4repair_space>valid<seq2seq4repair_space>competitor<seq2seq4repair_space>number" ) ; } break ; case "CLR" : break ; case "SWAP" : break ; case "RCL" : break ; case "START" : try { sensors . get ( 0 ) . trip ( ) ; } catch ( Exception e ) { System . out . println ( e . getMessage ( ) ) ; } break ; case "FINISH" : try { sensors . get ( 1 ) . trip ( ) ; } catch ( IllegalStateException e ) { System . out . println ( e . getMessage ( ) ) ; } break ; case "TRIG" : break ; default : System . out . println ( ( "Unknown<seq2seq4repair_space>command:<seq2seq4repair_space>" + ( arg [ 0 ] . toUpperCase ( ) ) ) ) ; } } private boolean isNum ( String str ) { } private boolean isChronoOn ( ) { } public static void main ( String [ ] args ) { } }

Fix:
chrono . print ( ) ;